Pension and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 48	$ 48	$ 52
Interest cost	46	45	57
Expected return on plan assets	(86)	(79)	(75)
Amortization of unrecognized prior service cost	(57)	(63)	(73)
Net loss (gain) amortization	(43)	(42)	(18)
Termination benefits	0	37	2
Curtailments	(1)	(29)	(4)
Settlements	0	0	0
Net periodic benefit cost (credit)	(93)	(83)	(59)
United States | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	372	403	360
Interest cost	457	404	431
Expected return on plan assets	(753)	(755)	(774)
Amortization of unrecognized prior service cost	(32)	(38)	(49)
Net loss (gain) amortization	128	298	303
Termination benefits	2	56	10
Curtailments	12	16	10
Settlements	239	216	13
Net periodic benefit cost (credit)	425	600	304
International | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	283	328	297
Interest cost	145	123	136
Expected return on plan assets	(383)	(416)	(414)
Amortization of unrecognized prior service cost	(14)	(16)	(18)
Net loss (gain) amortization	96	142	127
Termination benefits	1	5	3
Curtailments	0	(26)	0
Settlements	1	8	15
Net periodic benefit cost (credit)	$ 129	$ 148	$ 146